[PATCH v3] Add --emit-message-id flag to notmuch-insert.

[Brennan Vincent <brennan@umanwizard.com>]

It may be the case that a user (or script) wants to take some action
on a message immediately after inserting it. This can be done if one
knows the Message-ID with which the message was inserted. In order to
facilitate this use case, we add a flag "--emit-message-id" to notmuch
insert.

One example of a possible usecase (which is part of an upcoming patch)
is an emacs command to begin editing the current buffer as a draft.
---
 doc/man1/notmuch-insert.rst |  5 +++++
 notmuch-insert.c            | 24 ++++++++++++++++++++----
 test/T070-insert.sh         | 31 +++++++++++++++++++++++++++++++
 3 files changed, 56 insertions(+), 4 deletions(-)

diff --git a/doc/man1/notmuch-insert.rst b/doc/man1/notmuch-insert.rst
index e05bd0b5..141e5cb9 100644
--- a/doc/man1/notmuch-insert.rst
+++ b/doc/man1/notmuch-insert.rst
@@ -66,6 +66,11 @@ Supported options for **insert** include
    umask.  By default, delivered mail is only readable by the current
    user.
 
+.. option:: --emit-message-id
+
+   If the message was successfully inserted into the database,
+   print the message ID of the newly indexed message.
+
 .. option:: --decrypt=(true|nostash|auto|false)
 
    If ``true`` and the message is encrypted, try to decrypt the
diff --git a/notmuch-insert.c b/notmuch-insert.c
index e44607ad..05945a99 100644
--- a/notmuch-insert.c
+++ b/notmuch-insert.c
@@ -401,7 +401,8 @@ maildir_write_new (const void *ctx, int fdin, const char *maildir, bool world_re
 static notmuch_status_t
 add_file (notmuch_database_t *notmuch, const char *path, tag_op_list_t *tag_ops,
 	  bool synchronize_flags, bool keep,
-	  notmuch_indexopts_t *indexopts)
+	  notmuch_indexopts_t *indexopts,
+	  char **message_id_out)
 {
     notmuch_message_t *message;
     notmuch_status_t status;
@@ -441,8 +442,6 @@ add_file (notmuch_database_t *notmuch, const char *path, tag_op_list_t *tag_ops,
     }
 
   DONE:
-    notmuch_message_destroy (message);
-
     if (status) {
 	if (keep) {
 	    status = NOTMUCH_STATUS_SUCCESS;
@@ -458,6 +457,15 @@ add_file (notmuch_database_t *notmuch, const char *path, tag_op_list_t *tag_ops,
 	    }
 	}
     }
+    if (message_id_out) {
+	if (status == NOTMUCH_STATUS_SUCCESS) {
+	    *message_id_out = talloc_strdup(notmuch, notmuch_message_get_message_id(message));
+	} else {
+	    *message_id_out = NULL;
+	}
+    }
+    notmuch_message_destroy (message);
+
 
   FAIL:
     return status;
@@ -477,10 +485,12 @@ notmuch_insert_command (notmuch_database_t *notmuch, int argc, char *argv[])
     bool keep = false;
     bool hooks = true;
     bool world_readable = false;
+    bool emit_message_id = false;
     notmuch_bool_t synchronize_flags;
     char *maildir;
     char *newpath;
     int opt_index;
+    char *message_id;
     notmuch_indexopts_t *indexopts = notmuch_database_get_default_indexopts (notmuch);
 
     void *local = talloc_new (NULL);
@@ -491,6 +501,7 @@ notmuch_insert_command (notmuch_database_t *notmuch, int argc, char *argv[])
 	{ .opt_bool = &keep, .name = "keep" },
 	{ .opt_bool = &hooks, .name = "hooks" },
 	{ .opt_bool = &world_readable, .name = "world-readable" },
+	{ .opt_bool = &emit_message_id, .name = "emit-message-id" },
 	{ .opt_inherit = notmuch_shared_indexing_options },
 	{ .opt_inherit = notmuch_shared_options },
 	{ }
@@ -580,7 +591,8 @@ notmuch_insert_command (notmuch_database_t *notmuch, int argc, char *argv[])
     }
 
     /* Index the message. */
-    status = add_file (notmuch, newpath, tag_ops, synchronize_flags, keep, indexopts);
+    status = add_file (notmuch, newpath, tag_ops, synchronize_flags, keep, indexopts,
+		       emit_message_id ? &message_id : NULL);
 
     /* Commit changes. */
     close_status = notmuch_database_close (notmuch);
@@ -606,6 +618,10 @@ notmuch_insert_command (notmuch_database_t *notmuch, int argc, char *argv[])
 	}
     }
 
+    if (emit_message_id && message_id && status == NOTMUCH_STATUS_SUCCESS) {
+	printf("%s\n", message_id);
+    }
+
     if (hooks && status == NOTMUCH_STATUS_SUCCESS) {
 	/* Ignore hook failures. */
 	notmuch_run_hook (notmuch, "post-insert");
diff --git a/test/T070-insert.sh b/test/T070-insert.sh
index 73953272..6ae6abd0 100755
--- a/test/T070-insert.sh
+++ b/test/T070-insert.sh
@@ -257,6 +257,33 @@ test_expect_code 1 "notmuch insert < $gen_msg_filename 2>&1"
 
 notmuch config set new.tags $OLDCONFIG
 
+gen_insert_msg
+test_begin_subtest "--emit-message-id works"
+output=$(notmuch insert --emit-message-id < $gen_msg_filename)
+expected_msg_id=$(< $gen_msg_filename grep Message-Id | sed -E 's/^Message-Id: <(.*)>$/\1/')
+test_expect_equal "$output" "$expected_msg_id"
+
+test_begin_subtest "--emit-message-id works even when the message already exists"
+output=$(notmuch insert --emit-message-id < $gen_msg_filename)
+expected_msg_id=$(< $gen_msg_filename grep Message-Id | sed -E 's/^Message-Id: <(.*)>$/\1/')
+test_expect_equal "$output" "$expected_msg_id"
+
+gen_insert_msg
+test_begin_subtest "--keep --emit-message-id works when maildir flag sync fails"
+make_shim shim-failed-sync <<EOF
+#include <notmuch.h>
+notmuch_status_t
+notmuch_message_tags_to_maildir_flags (notmuch_message_t *message)
+{
+  return NOTMUCH_STATUS_OUT_OF_MEMORY;
+}
+EOF
+notmuch config set maildir.synchronize_flags true
+output=$(notmuch_with_shim shim-failed-sync insert --keep --emit-message-id < $gen_msg_filename)
+expected_msg_id=$(< $gen_msg_filename grep Message-Id | sed -E 's/^Message-Id: <(.*)>$/\1/')
+test_expect_equal "$output" "$expected_msg_id"
+notmuch config set maildir.synchronize_flags false
+
 # DUPLICATE_MESSAGE_ID is not tested here, because it should actually pass.
 # pregenerate all of the test shims
 for code in FILE_NOT_EMAIL READ_ONLY_DATABASE UPGRADE_REQUIRED PATH_ERROR OUT_OF_MEMORY XAPIAN_EXCEPTION; do
@@ -282,6 +309,10 @@ for code in FILE_NOT_EMAIL READ_ONLY_DATABASE UPGRADE_REQUIRED PATH_ERROR; do
 
     test_begin_subtest "success exit with --keep when index_file returns $code"
     test_expect_code 0 "notmuch_with_shim shim-$code insert --keep < \"$gen_msg_filename\""
+
+    test_begin_subtest "nothing printed even with --keep --emit-message-id  when index_file returns $code"
+    output=$(notmuch_with_shim shim-$code insert --keep --emit-message-id < $gen_msg_filename)
+    test_expect_equal "$output" ""
 done
 
 for code in OUT_OF_MEMORY XAPIAN_EXCEPTION ; do
-- 
2.46.0